Tying to its earlier reports over the role of the iron compounds and the humin substances with the feature of the coloring of water and over the elimination of this substances under influence of sunlight, etc. (Bulletin Acad. roy. Bolgique [3] 34. 578; C. 98. I. 410 and Rec. trav. chim. Pays-Bas 17. 202; C. 98. II. 224) author the cause of the colorlessness many discusses clear waters, about what already Berzelius (Annual Report f. Chemistry 9. 207) expressed its astonishment. Terrestrial water only very rarely will appear blue, since in all ground are traces of hematite, and this the blue color water for our eye compensates. On the other hand the glaciers and the snow of high peaks do not contain hematite, water from high regions throw their blue and therefore can maintain their color. Furthermore the influence of the iron compounds on the coloring water is very differenct, depending on whether they are in the form of their hydrates or anhydrous oxides in the water; into latter trap they step with the Humin or the organic substances water not into reaction, the water more generally continues to appear colorless.